Breast cancer imaging with In-111 human IgM monoclonal antibodies: preliminary studies.

Detection of specific tumor sites was studied with scintigraphy and radiolabeled human IgM monoclonal antibodies (MoAbs). Ten patients with metastatic breast cancer received an infusion of one of three indium-111-labeled anti-breast carcinoma MoAbs. The time of infusion ranged from 30 minutes to 2 hours. Three patients received YBB-190 at total doses of 2, 4.25, or 11 mg, four patients received YBM-209 at total doses of 1 mg (n = 1) or 20 mg (n = 3), and three patients each received 22 mg of YBY-088. Imaging was performed immediately after infusion and at 4, 24, 48, 72, 120, and 144 hours. Many presumed sites of metastatic disease were imaged in three of the four patients who received 20 mg of YBM-209 and in two of the three patients who received YBY-088. Tumor was not detected in any of the patients who received YBB-190, in the patient who received a 1-mg dose of YBM-209, or in the patient who received YBY-088 and in whom a biopsy of tumor tissue failed to demonstrate target antigen. The authors conclude that In-111-labeled human IgM MoAbs can target human breast cancer, but antigen expression and antibody dose determine successful immunoscintigraphy.